/*
 * Copyright 2007 Rob Nielsen
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * 	http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.googlecode.proxymatic.apps.autoboundary.handlers;

import com.googlecode.proxymatic.apps.autoboundary.AutoboundaryLookup;
import com.googlecode.proxymatic.core.ReturnTypeModifier;

import java.lang.reflect.Method;

public class AutoboundaryReturnTypeModifier implements ReturnTypeModifier {
    private final AutoboundaryLookup autoboundaryLookup;
    private final AutoboundaryWrapperUnwrapper autoboundaryWrapperUnwrapper;

    public AutoboundaryReturnTypeModifier(AutoboundaryLookup autoboundaryLookup, AutoboundaryWrapperUnwrapper autoboundaryWrapperUnwrapper) {
        this.autoboundaryLookup = autoboundaryLookup;
        this.autoboundaryWrapperUnwrapper = autoboundaryWrapperUnwrapper;
    }

    public Object modifyReturnType(Method method, Object returnObject, Class returnType) {
        Class expectedReturnType = method.getReturnType();
        if (expectedReturnType.equals(void.class)) {
            return null;
        }
        if (expectedReturnType.isAssignableFrom(returnType)) {
            return returnObject;
        }
        return autoboundaryWrapperUnwrapper.getObject(expectedReturnType, returnType, returnObject);
    }

    public boolean supportsReturnType(Class fromReturnType, Class toReturnType) {
        return toReturnType.equals(void.class) ||
                toReturnType.isAssignableFrom(fromReturnType) ||
                supports(fromReturnType, toReturnType) ||
                supports(toReturnType, fromReturnType);
    }

    private boolean supports(Class autoboundaryClass, Class realClass) {
        boolean autoboundaryPair = autoboundaryLookup.isAutoboundaryAssignablePair(autoboundaryClass, realClass);
        if (autoboundaryPair) {
            autoboundaryWrapperUnwrapper.ensureHandled(autoboundaryClass, autoboundaryLookup.getRealClass(autoboundaryClass));
        }
        return autoboundaryPair;
    }
}